4,207 research outputs found

    Towards compliant data retention with probe storage on patterned media

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    We describe how the compliance requirements for data retention from recent laws such as the US Sarbanes Oxley Act may be supported by a tamper-evident secure storage system based on probe storage with a patterned magnetic medium. This medium supports normal read/write operations by out-of-plane magnetisation of individual dots. We report on an experiment to show that in principle the medium also supports a separate class of write-once operation that destroys the out-of-plane magnetisation property of the dots irreversibly by precise local heating. The write-once operation can be used to support flexible data retention by tamper-evident writing and physical data deletion

    Lambda Calculus for Engineers

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    In pure functional programming it is awkward to use a stateful sub-computation in a predominantly stateless computation. The problem is that the state of the subcomputation has to be passed around using ugly plumbing. Classical examples of the plumbing problem are: providing a supply of fresh names, and providing a supply of random numbers. We propose to use (deterministic) inductive definitions rather than recursion equations as a basic paradigm and show how this makes it easier to add the plumbing

    On the evaluation of Web Radio

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    We develop an evaluation method for Web radio, and perform it to see what we can be learnt about seven prominent Web radio sites. We also evaluate a commercial FM radio station for control purposes. We present a taxonomy of Web radio, and we give our observations and conclusions on this evaluation

    The Resource constrained shortest path problem implemented in a lazy functional language

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    The resource constrained shortest path problem is an NP-hard problem for which many ingenious algorithms have been developed. These algorithms are usually implemented in FORTRAN or another imperative programming language. We have implemented some of the simpler algorithms in a lazy functional language. Benefits accrue in the software engineering of the implementations. Our implementations have been applied to a standard benchmark of data files, which is available from the Operational Research Library of Imperial College, London. The performance of the lazy functional implementations, even with the comparatively simple algorithms that we have used, is competitive with a reference FORTRAN implementation

    Smart Device Profiling for Smart SCADA

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    SCADA (Supervisory Control and Data Acquisition) systems are computer systems used for monitoring and controlling industrial processes such as power plants and power grid systems, water, gas and oil distribution systems, production systems for food, cars and other products. We propose a new approach for regulating and detecting malicious behaviour of network devices in SCADA systems. Our approach consists of building proles that describe normal communication between pairs of devices in the network. Each prole describes four aspects of network communication: device ngerprint, connectivity pattern, pseudo-protocol pattern and packet content. We validate our approach using network trac from two real-life SCADA installations

    Cyber-crime Science = Crime Science + Information Security

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    Cyber-crime Science is an emerging area of study aiming to prevent cyber-crime by combining security protection techniques from Information Security with empirical research methods used in Crime Science. Information security research has developed techniques for protecting the confidentiality, integrity, and availability of information assets but is less strong on the empirical study of the effectiveness of these techniques. Crime Science studies the effect of crime prevention techniques empirically in the real world, and proposes improvements to these techniques based on this. Combining both approaches, Cyber-crime Science transfers and further develops Information Security techniques to prevent cyber-crime, and empirically studies the effectiveness of these techniques in the real world. In this paper we review the main contributions of Crime Science as of today, illustrate its application to a typical Information Security problem, namely phishing, explore the interdisciplinary structure of Cyber-crime Science, and present an agenda for research in Cyber-crime Science in the form of a set of suggested research questions

    On consistency maintenance in service discovery

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    Communication and node failures degrade the ability of a service discovery protocol to ensure Users receive the correct service information when the service changes. We propose that service discovery protocols employ a set of recovery techniques to recover from failures and regain consistency. We use simulations to show that the type of recovery technique a protocol uses significantly impacts the performance. We benchmark the performance of our own service discovery protocol, FRODO against the performance of first generation service discovery protocols, Jini and UPnP during increasing communication and node failures. The results show that FRODO has the best overall consistency maintenance performance

    Scheduling Optimisations for SPIN to Minimise Buffer Requirements in Synchronous Data Flow

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    Synchronous Data flow (SDF) graphs have a simple and elegant semantics (essentially linear algebra) which makes SDF graphs eminently suitable as a vehicle for studying scheduling optimisations. We extend related work on using SPIN to experiment with scheduling optimisations aimed at minimising buffer requirements.We show that for a benchmark of commonly used case studies the performance of our SPIN based scheduler is comparable to that of state of the art research tools. The key to success is using the semantics of SDF to prove when using (even unsound and/or incomplete) optimisations are justified. The main benefit of our approach lies in gaining deep insight in the optimisations at relatively low cost

    Benchmarking Block Ciphers for Wireless Sensor Networks

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    Choosing the most storage- and energy-efficient block cipher specifically for wireless sensor networks (WSNs) is not as straightforward as it seems. To our knowledge so far, there is no systematic evaluation framework for the purpose. We have identified the candidates of block ciphers suitable for WSNs based on existing literature. For evaluating and assessing these candidates, we have devised a systematic framework that not only considers the security properties but also the storage- and energy-efficency of the candidates. Finally, based on the evaluation results, we have selected the suitable ciphers for WSNs, namely Rijndael for high security and energy efficiency requirements; and MISTY1 for good storage and energy efficiency
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